Tailstock clamp unit



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w. v. SCHMIDT 2,802,385

Aug. 13, 1957 TAILSI'OCK CLA P UNIT Filed Nov. 4, 1953 2 Sheets-Sheet l S I 60 f Ff T 14 r 60 v 48 '46 Fig.3

V .40 42 12 w Waller l/. Schmidt 44 44 INVENTOR.

2a a a v 50 46' v mwflhm Aug. 13, 1957 7 Filed Nov. 4, 1953 W. V. SCHMIDT TAILSTOCK CLAMP UNIT 2 Sheets-Sheet 2 JNVENTOR.

can Wavy M if" 2,802,385 Fatented Aug. 13, 1957 ranls'rocrr CLAMP UNIT Waiter v. Schmidt, Highland Falis, N. Y.

Application November 4, 1953, Serial No. 390,136 2 claims. or. 82--31) This invention relates generally to lathe accessories, and pertains more particularly to an improved mechanism for selectively locking the tailstock assembly of a lathe in thedesired position on its ways.

A primary object of this invention is to provide an improved locking mechanism for tailstocks, which is readily adapted to existing tailstocks and which may be operated in a rapid and efficient manner.

Another object of this invention is to provide an improved cam lock in conformity with the foregoing objects which incorporate a clamping lock journaling an actuating shaft therein, the actuating shaft having an eccentric portion, and a connecting member journaled on the eccentric portion and adapted for connection to a tailstock such that rotation of the actuating shaft will selectively clamp and release the ways of a lathe for positioning the tailstock thereon in the desired position.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a perspective view of a portion of a lathe bed, showing a tailstock mounted thereon by means of the approved cam lock;

Figure 2 is an enlarged vertical section taken through a portion of the tailstock assembly shown in Figure 1;

Figure 3 is a transverse vertical section, taken substantially along the plane of section line 3-3 in Figure 2;

Figure 4 is an exploded perspective view of the cam lock attachment; and

Figure 5 is an exploded perspective view of a modified form of the invention.

Referring now more particularly to Figure 1, reference numeral It) indicates generally the bed of a lathe which incorporates the usual ways 12 for supporting the tailstock assembly 14 thereon, the tailstock incorporating the usual base plate member 16 and the main body portion 13 which is provided with the usual opening or recess as at 26, the bottom surface of which is provided with the conventional vertical opening 22 through which the usual clamping bolt extends, the purpose of the opening 20 being to permit the insertion of a Wrench to manipulate the locking nut provided on the usual clamping bolt such that the tailstock may be selectively moved longitudinally of the ways and locked in a desired position.

As seen most clearly in Figure 2, the under surface of the tailstock plate 16 is provided with the conventional transverse rib 24 extending between the ways 12, it being understood that in those structures not employing such a bottom plate, the invention contemplates the provision of such.

The invention consists more particularly of a clamping lock member, indicated generally by the reference character 26, which has a pair of end wall members 28 provided with a pair of aligned openings 30 and 32 therein adapted to receive and journal the longitudinally spaced bearing surfaces 34 and 36 of the actuating shaft assemblies 38 respectively. The opposite side walls 40 and 42 of the clamping block-s are provided at their opposed edges with cutaway portions defining the rib 44 adapted to project beneath and underlie the inner flanges of the ways 12 in the manner shown most clearly in Figure 3. An eccentric portion 46 of the shaft assembly 38 is provided between the bearing surfaces 34 and 36, this eccentric portion lying within the recess defined by the walls 28, 40 and 42, respectively.

A connecting member indicated generally by the reference character 48 includes an enlarged boss-like lower end portion 50 having an opening 52 receiving the eccentric portion of the shaft assembly and having its opposite end faces disposed closely adjacent the inner surfaces of the end walls 28. The upper portion of this connecting member is of rod-like configuration and is threaded at its upper extremity as indicated by the reference character 54 to receive the nut member 56 and associated washer 58, this upper end of the connecting member projecting through the previously described opening 22 in the tailstock so as to becarried in depending relation thereto.

A bearing bracket 60 is secured to one end of the platemember 16 in the manner'shown most clearly in Figures 1 and 2, this bracket being transversely split and provided at its mating edges with registering semi circular notches to embrace an intermediate portion of the shaft assembly 38 for steadying the same. The shaft assembly is provided with an enlarged collar portion 62 adapted to engage the outer face of one end wall 28 of the clamping block assembly 26 and the free end of the shaft assembly is threaded as indicated at 64 to receive a retaining nut 66 and suitable Washer member, if desired, such that the shaft assembly is fixed longitudinally with respect to the clamping block 26. The opposite end of the shaft member is provided with an upturned handle portion 68 which may be provided at its free end with a knob member 70.

In operation, it will be manifest that the nut member 56 is originally manipulated to produce the desired clamping effect of the block assembly 26 when the shaft assembly is rotated into one position through manipulation of the handle portion 68 thereof and the shaft assembly, when rotated to another position through the handle portion will disengage the clamping block 26 from the under surface of the ways 12, permitting the tailstock assembly to be moved longitudinally to any desired position along these ways. This completely obviates the necessity of manipulating the conventional nut member corresponding to the nut member 56 every time it is desired to move the tailstock longitudinally on the lathe ways, it being manifest that the sheer manipulation of the handle member 68 of the shaft assembly 38 will selectively clamp or unclamp the tailstock assembly to the lathe bed assembly.

As seen most clearly in Figure 5, the modified form of clamping block assembly 72 may be provided, portions of the opposite side walls 74 thereof being adapted to underlie the lathe ways. The end walls 76 are provided with the registering apertures 78 to receive bearing surfaces of the shaft assembly 80 which differs from the previously described shaft assembly 38 only in the respect that the handle portion 82 thereof is formed as a hand grip. This form of the invention may be utilized with tailstock assemblies not having a base plate 16 or wherein it is not desired to provide such a base plate as a cooperating accessory.

From the foregoing, the construction and operation of the device will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claims.

What is claimedtas new is as follows:

1. A cam clamp unit for use with lathes, comprising a clamp bar for reception in the clamp slot of the bed of a lathe and adapted to be forced against the flanges thereof, said clamp bar having a pair of spaced end walls defining a recess therebetween, said walls having aligned bearing bores, an actuator member having one end provided with'a bearing bore and received in said recess with its other end having means for attachment to a tailstock in the usual manner, a camrning shaft for said actuator passing through said bores and comprising a reduced end portion journaled through one end of said walls, a larger diameter portion journaled through the other of said walls, and an eccentric portion between said journaled portions and journaled through said actuator, and a nut on said reduced end portion, said nut and cam portion abutting opposite sides of one of said walls to locate said shaft axially, said actuator being confined between said one wall and said larger diameter portion to locate the actuator axially of said shaft, said cam shaft being extended and an actuating lever secured to said extention.

2. A cam clamp unit for use with lathes, comprising a K a clamp bar for reception in the clamp slot of the bed of a lathe and adapted to be forced against the flanges thereof, said clamp bar having a pair of spaced end walls defining a recess therebetween, said Walls having aligned bearing bores, an actuator member having one end provided with a bearing bore and received in said recess with its other end having means for attachment to a tailstock in the usual manner, a camming shaft for said "actuator passing through said bores and said cam shaft being extended, and an actuating lever secured to said extention.

References Cited in the file of this patent UNITED STATES PATENTS 257,883 McMahon May 16, 1882 646,750 Mill Apr. 3, 1900 981,426 Hjorth Jan. 10, 1911 991,675 Vold May 9, 1911 1,490,405 Stanton Apr. 15, 1924 1,616,136 Moyer Feb. 1, 1927 1,664,757 Randolph Apr. 3, 1928 1,966,409 Hoelscher July 10, 1934 2,430,677 Hobart Nov. 11, 1947 FOREIGN PATENTS 7,632 Austria May 26, 1902 Great Britain Apr. 19, 1906 

